North Korea has condemned the United States missile attack against a Syrian airfield, calling it a clear and unforgivable act of aggression against a sovereign state.

The North’s official Korean Central News Agency quoted a spokesman for the North Korean foreign ministry as saying on Saturday that there are speculations that the strikes contained a clear message for Pyongyang, but the attack does not affect or surprise the North.

Pyongyang said that the Syrian attack proves a million times over that strengthening its nuclear program was the right choice, vowing to keep bolstering its self-defensive military might in various ways in order to cope with the ever-intensifying U.S. acts of aggression.

White House spokesman Sean Spicer said on Friday that the Syrian attack sends a very strong signal not just to Syria but throughout the world.